Vitatron G20 SR Single Chamber Pacemaker System


Model G20A1
Size (HxWxD mm) 40.2x42.9x7.5
M (g) 21.5
V (cc) 9.7
Connector IS-1 BI or UNI
Radiopaque ID VG
Type Lithium-iodine
Voltage 2.8 V
Average projected capacity .92 Ah
Longevity 10.4 years*

Bradycardia Pacing

Programmable Parameters

Parameter Name Range Nominal Value
Lower rate 30, 35, 40…60…170, 175 ppm (exc. 65, 85) 60 ppm
Upper Sensor Rate 80, 90, 95…130…180 ppm 130 ppm
A and RV Pulse Amplitudea 0.5, 0.75, 1.0…3.5…4, 4.5, 5, 5.5, 6, 7.5 V 3.5 V
A and RV Pulse Width 0.12, 0.15, 0.21, 0.27, 0.34, 0.4, 0.46, 0.52, 0.64, 0.76, 1, 1.25, 1.5 ms 0.4 ms
Atrial Sensitivity 0.25, 0.35, 0.5, 0.7, 1, 1.4, 2, 2.8, 4 mV 0.5 mV
Ventricular sensitivity 1, 1.4, 2, 2.8, 4, 5.6, 8, 11.2 mV 2.8 mV
Pacing Polarity (A and V) Bipolar, Unipolar, Configure  
Sensing Polarity (A and V) Bipolar, Unipolar, Configure  
Atrial Refractory Period 180, 190, 200…250…500 ms 250 ms
Atrial Blanking Period 130, 140, 150…180…350 ms 180 ms
Ventricular Refractory Period 150, 160, 170…330…500 ms 330 ms
Therapies to promote intrinsic activation
  • Sleep Rate
  • Bed Time
  • Wake Time
On, Off
30, 35, 40…50…90 ppm (exc. 65, 85)
00:00, 00:15, 00:30…22:00…23:45
00:00, 00:15, 00:30…8:00…23:45
50 ppm
Single Chamber Hysteresis Off, 40, 50, 60 ppm Off

Rate Response Pacing

Parameter Name Range Nominal Value
ADL Rate 60, 65, 70…95…175, 180 ppm 95 ppm
Rate Profile Optimization On, Off On
ADL Response 1, 2, 3, 4, 5 3
Exertion Response 1, 2, 3, 4, 5 3
Activity Threshold Low, Medium Low, Medium High, High Medium Low
Acceleration 15 s, 30 s, 60 s 30 s
Deceleration 2.5 min, 5 min, 10 min, Exercise Exercise

Atrial Tachyarrhythmia Therapies and Interventions

Conducted AF Responseb

Parameter Name Range Nominal Value
Regularize V-V during AT/AF On, Off Off
Maximum Rate (ppm) 80, 85, 90…110…130 110

Automatic Pacing, Sensing, and Lead Monitor

Implant Detection and Initialization

At the completion of the 30-minute Implant Detection period, Rate Profile Optimization is enabled; the appropriate pacing and sensing polarities are automatically selected by the device; Ventricular Output Management is enabled and Amplitude and Pulse Width become adaptive. Sensing Assurance™ is enabled and Sensitivity becomes adaptive.

Implant Detection On/Restart, Off/Complete
Lead Monitor (A and V) Configure, Monitor Only, Adaptive
(Auto Polarity Switch), Off
Parameter Name Range Nominal Value
Notify If < 200 Ω 200 Ω
Notify If > 1000, 2000, 3000, 4000 Ω 4000 Ω
Monitor Sensitivity 2, 3, 4 … 8 … 16 8

Ventricular Output Management

Parameter Name Range Nominal Value
Ventricular Output
Management Off, Monitor Only, Adaptive Adaptive
Amplitude Margin 1.5x, 2x, 2.5x, 3x, 4x (times) 2x
Minimum Adapted Amplitude 0.5, 0.75…2…3.5 V 2
Capture Test Frequency 15, 30 min; 1, 2, 4, 8, 12 hours; Day at rest; Day at…; 7 days at Day at rest
Capture Test Time 00:00, 1:00…23:00
Acute Phase Days Remaining Off, 7, 14, 21…84, 112, 140, 168… 252 days 112 days
V. Sensing During Search Unipolar, Bipolar, Adaptive Adaptive

Sensing Assurance

Parameter Name Range Nominal Value
Sensing Assurance (A and V) On, Off On


Cardiac Dashboard II
Highlights significant events, AT/AF and pacing summary, threshold and impedance trends

Ventricular pacing threshold trends
Battery longevity
Pacing summary and access to rate histogram
Atrial and ventricular lead impedance trends
Number of hours/day in atrial arrhythmia, percentage of time
Access to AT/AF diagnostics
P-wave/R-wave amplitudes and access to A and V sensitivity trends

AT/AF compass trends
Trend data compiles up to 6 months of daily clinical information in an easy-to-interpret graphic format

Histogram reports

Heart rate histograms
Sensor indicated rate profile

Atrial and ventricular episodes

High rate episodes
Atrial arrhythmia durations
Multiple EGM episodes
AT/AF duration

Clinician selected diagnostics

Custom rate trend
Ventricular Output Management detail
High rate detail

Patient Data Management

Patient data stored in device

Patient identification
Leads implanted
Device implanted
Clinician’s stored notes

Data management

Automatic printing of initial interrogation report
Full page printing
Save-to-Disk capacity for electronic file management

Follow-up and Troubleshooting

Telemetry features
Transtelephonic monitor On, Off
Extended telemetry On, Off
Extended marker Standard, Therapy Trace

Key parameter history
Initial interrogation report
Strength duration threshold test
Ventricular threshold test
Marker Channel™
Threshold margin test
Exercise test
EP studies
Magnet test
Underlying rhythm test
Sensing test
Temporary test

Magnet mode operation

Single chamber atrial mode AOO 85 ppm 65
Single chamber ventricular mode VOO 85 ppm 65
ERI-RRT Initiation Date

Recommended Replacement Time (RRT/ERI)

Replacement message on programmer (Cardiac Dashboard II)
Battery/lead information Replacement message and displayed battery voltage on programmer
RRT/ERI initiation date Displayed on programmer


a Tolerance for amplitudes from 0,5V through 6.0V is ± 10%, and for 7,5V is -20/+0%. Tolerances are based on 37°C and a 500± load. Amplitude is determined 200 μs after the leading edge of the pace.
b Conducted AF Response is functional during WIR modes.
*SSIR or SSI, 60 ppm, 100% pacing, 2.0V, 0,4 ms pulse width, 1000Ω pacing impedance.

G20 SR